Varies of vitamins are critical for eyes. For example, when vitamin B2 deficiency will occur on conjunctivitis, keratitis, and can even lead to cataracts. Vitamin A deficiency will cause night blindness and may lead to damage of the optic nerve. As for vitamin C, which deficiency can also cause cataracts, usually, it is obtained from a variety of fresh vegetables and fruits. Several bad dietary diets impact eyesight: 1. eating sweet foods (including a variety of sweet drinks) has great influence on vision. 2. Only eat meat and fine food, not eating or eating fewer vegetables. 3. Only eat vegetables, not eating or eating less meat.